Method of die rolling



Aug. 31., 1926.

1,597,955 P. L. COYLE METHOD OF DIE ROLLING Filed 001;. 6, 1925 INVENTORPatented Aug. 31 1926.

UNITED STATES PAUL Ia com, 01' YITTBBUBGH, PENNSYLVANIA,

ASSIGHOR '10 7 WITHEROW STEEL comm, 01' PITTSBURGH, PENNBILVANIA, ACORPORATION OI PENNSYL- VANIL- HE'IHOD OF DIE ROLLING.

Application fled mm 0, 1m. sums. 00,191.

This invention relates to die rolling, and articularly to a methodwhereby the useful ife of a pair of die rolls may be multiplied manytimes with an expense which is very 6 slight compared with the'expenseof a new set of rolls. 7

Die rolling is a pair of rolls having matrix portions cut therein and,particularly in those. rtions to of the roll where a heavy reduction 18efiected, the rolled metal at the corner of the matrix portion and theperiphery of the roll becomes badly pitted and worn. In addition' tothis, various o er portions of the 1 roll which come in contact with thehot metal are pitted or cracked and as a resuit the roll soon becomesunfit for. further production. Generally speaking, the mg factor on themill run of any particuw lar sha is the wear on the rolls, and after acertain len h of time, even though regrinding w e the'rolls are inthermll in place is practiced as disclosed in the 'copending a licationof William P. Witherow, Serlal' 0. 44,111, filed July 16 1925, the rollsare no longer lit for the re action of commercial articles and scrap edor else out down to such diameter that t 0 matrix portions have beenentirely a removed and the smooth rolls of smaller diameter thusprovided are used in,the 'production of smaller articles.

I provide for ereduci'ng the diameter of a used roll slightly andworking out the matrix portion to substantiall its original depth. Forexample, a roll or the production of a rear axle shaft for automobilesmay have a matrix portion which in some laces is nearly an inc "deep.When a roll of this character has been worn out it is placed in a latheand reduced in diameter cm to inches and the m rix portions are recut tosubstantially eir original de th.

twill be ap portions will be reduced somewhat in their length and I havefound 5 by actual'experience that the reduction in diameter andcorresponding reduction of the length of the matrix portions is ofi'setin a large degree by an increased extrusion efi ect roduced by being t ecase, a reduction of f; of an inch,

or even 011% of an inch, in diameter, with the corresponding shorteningof the matrix process the matrix accomplished by the use of.

hereto ore have been preciated that durin this production 0 the smallerroll. Thisportions of the roll does not arlgreciahl afiect the length.in other wo a re ma be redressed once and sometimes twice wit out anyattemptto increase the length of matrix rtions to their original lengthand. the ro will nevertheless reduce ar-. ticles of desired dimensions.En practice rollshave been redressed as many as five times, but it isfound thatafter the second redressing the matrix portions should belengthened somewhat as the extrusion efiect does not increase readilyenough to compensate for the reduction in l h of the matrix portions.

Provision is t erefore made in the original roll of a gate betweensuccessive article producing rtions in the roll and this gate 13shortene on successive redressings.

Very frequently it is found, es ecially with rolls made of such allo sas a amite that the desirable characteristics of the roll material areenhanced during the first and that as a result a redressed roll standsup better on successive runs than does a new. of decided valuefor roll.This, of course, 15 so it tends to reduce the lost mill time.

In the accompanying drawings illustratin one application. of myinvention:-

igure 1 is a transverse section through a die roll indicating the mannerof redressing in chain lines;

' F-i e 2 is a section on the line II--II of Figure 1', and a Figure 8is a side elevation of a die axle blank produced by the roll shown inFigures 1 and 2.

In the-"illustrated embodiment of the invention there is shown one of apair of die rolls ada ted for the production of a rear axle sha such asshown in Figure 3. The roll is what is called a two-impression roll.That is to say, it produces two axleson a single revolution. Each ofthese impressions comprises a matrix portion 2 for the production githeshort taper 2 on the axle shaft; a portion 3 for the production of theso-called lon taper 3*; a portion 4 for the i the stubportlcn t, and aportion 5 for producing a gate between adjacent axles on a at g ofdie'rolled blanks. The 105 roll is preferably provided with four groovesG as shown in, Figure 2, each 0 these grooves being identical.

The roll, with its companion, the mill and a run is commenced.

is placed in The no various grooves are used in succussion until all ofthem are worn out. They may then be renewed one or more times bygrinding or polishing the matrix portions inrthe mill as set out in myapplication above mentioned,

but sooner or later all of the grooves will be worn to such an extentthat the roll in its then condition isno longer capable of producingcommercial axles.

The roll is removed from the mill and returned to the roll shop where itis placed between centers and turned down a small amount. In practice itis found that a reduction in diameter of 3,4; or inches is sufficient.This reduction in diameter is indicated in Figure 1 in heavy chain line6. It is next necessary to deepen the matrix portions a correspondingamount and this may be done in any desired way. It is found in practicethat the reduced diameter roll has an increased extrusion efl'ect and asa result the, various matrix portions need not be so long as they wereon the original roll. It is found for the first, and possibly thesecohd, redressing, that if all of the matrix portions are simp yincreased in depth an amount corresponding to the decrease in radius ofthe r0 1, satisfactory results will be obtained in rollin This isindicated by the heavy chain line in Figure 1. H

After one or two redressin the increased extrusion efl'ect is notsuflicient to produce articles of the desired length and the matrixortions are then increased somewhat in iimgth by incroaching on the gateproducing matrix. This results in a string of articles with a shortergate in between, but since this metal goes to scrap the desired resultsare obtained.

The greatest wear on the rolls occurs at the corners C and, of course,these corners are com letel' removed by the redressing process. t isound in practice that in man cases the characteristics of the rolledmetal have been materially improved by the first workin so that aredressed roll will do considerab y more work than a new roll. Inaddition to this, it is, of course, much easier to work out the oldmatrix portion to desired dimensions than it is to cut an entirely newroll. The old matrix portions serve as a ide for the cutting tools andwith a litte experience a competent roll maker can increase the lengthof the matrix portions sli htly if it becomes necessary and put the rolin shape for again producing the desired articles without recourse tothe extensive calculations and-close supervision which are necessary inthe original design of the roll. Generally s eaking, the roll makersimply follows the o (1 matrix portions and redresses the entireperipheral surface of the roll.

The drawings show a roll having semicircular matrix portions therein,but oh viously the invention is applicable to other types of rolls. Forexample, in a roll having rectanguar matrix portions the advantages ofmy invention may be obtained by dressing simply the periphery of theroll and the bottom of the matrix portions. There is usually provided aslight draft on the sides of such rectangular matrix portions and thesewill also be dressed. The invention is applicable to die rolls for theproduction of practically every article which may be made by thatrocess. Therefore, while I have illustrate and described one embodimentof the invention, it will be understood that it is not thus limitedsince it may be otherwise embodied or racticed within the scope of thefollowing o aims,

I claim:

1. The method of die rollin which includes reducing the diameter o aused roll having a matrix portion therein deepenin the matrix portioncorrespondingly, an utilizing the increased extrusion effect of thesmaller ro'll thus produced to compensate for the shortened matrix andproduce a die rolled article of, substantially the same length as wasroduced by the original roll, substantially 8. described.

2. The method of die rollin which includes reducing the diameter 0% aused roll having a matrix portion therein, working out the matrixportion to substantially its original de th, and utilizing the increasedextrusion e ect of the smaller roll thus produced to compensate for theshortened matrix'and produce a die rolled article of substantially thesame length as was produced by the original roll, substantially asdescribed.

3. The method of die rollin which includes reducin the diameter 0 aroll, and

utilizing the increased extrusion efiect of the smaller roll thusproduced to secure die rolled articles of substantially the lengthproduced by theoriginal roll, substantially as describe 4. The method ofdie rolling which includes reducing the diameter oi a die roll havingmatrix portions therein, working out such matrix fportions to producematrix portions 0 substantially the same dimensions in cross section asthe matrix portions of the original roll in cross section and shorteraround the perimeter of the roll than the matrix portions of suchoriginal roll, and utilizing the increased extrusion effect of thesmaller roll thus produced to. compensate for the shortened matrix andproduce a die rolled article of substantially the same length as wasproduoed by the original roll, substantially as described.

5. The method of die rolling, which includes using a roll until it issubstantially worn out, then redressing the roll over sub stantially itsentire peripheral surface, and utilizing the increased extrusion effectof the smaller roll thus produced to compensate for the shortened matrixand produce a die rolled article of substantially the same length as wasproduced by the original roll, substantially as described.

6. The method of using a die roll having matrix portions thereinconnected by a gating, which includes reducing the diameter of the rollafter ithas been used, deepening the matrix portions, and encroachingupon the gating to secure the desired length for the matrix portions,substantially as described.

7. The method of die rolling, which includcs forming matrix portions ina die roll for the production of corresponding article portions ofdesired length, using the roll for a desired length of time, and thenreducing the diameter of the roll and redressing the matrix portions,the redressed matrix portions being of shorter length than the originalmatrix portions in accordance with the my hand.

PAUL L. COYLE.

worn out, then redressing the roll over substantially its entireperipheral surface, and utilizing the increased extrusion effect of thesmaller roll thus produced to compensate for the shortened matrix andproduce a die rolled article of substantially the same length as wasproduced by the original roll, substantially as described.

6. The method of using a die roll having matrix portions thereinconnected by a gating, which includes reducing the. diameter of the rollafter ithas been used, deepening the matrix portions, and encroachingupon the gating to secure the desired length for the matrix portions,substantially as described.

7. The method of die rolling, which innal matrix portions in accordancewith the reduced diameter of the roll so as to utilize the increasedextrusion effect of the reduced diameter roll and thus produce articleportions of substantially the same length as those produced by theoriginal matrix portions.

In testimony whereof I have hereunto set my hand.

PAUL L. COYLE.

D ISO LA M E R l.597',955.'-[auZ 11. 07 70. Pittsburgh, Pa. METHOD OFDH: ROLLING. Patent dated August 31, 1926.

Disclaimer filed March 28, 1928, by the assignments, The (/olom'al TmstCompany, trustee.

assignee, by mesne Hereby disclaims from claim 6 any method of using adie roll except where the matrix portions of the die roll are soproportioned relatively to one another that flash is, produced alongboth sides of at least a part of the article during the die rollinoperation.

[01%01212 Gazette April 10, 1928.]

DISCLAI M E R 1.597,955.-Pm)l L (7031b. Pittsburgh, Pa. Mm-uon or Du:Romano. Patent dated August 31, 1926. Disclaimer filed March 28,1928, bythe assignee, by mesne assignments, The Colonial Tms't Company, trustee.Hereby disclaims from claim 6 any method of using a. die roll exceptwhere the matrix portions of the die r011 are so proportioned mlativelyto one another that flas]; is produced along both sides of at least a.part of the article during the die :011111 operation.

[Ojicial Gazette A n? 10, 1928.]

